Animated image text overlay

• Choose the base animated GIF, APNG or WebP.
• Enter the caption, placement, font size, color, outline and active time range.
• Choose output format and total plays, compose, preview and download the animation and timing manifest.

Show “Hello” from 40 ms through 180 ms of an animation, with white text and a black outline.

• Animated GIF, APNG and WebP inputs are fully composited with their blend/disposal rules before editing. APNG support is non-interlaced 1–8-bit grayscale/palette or eight-bit RGB/RGBA; re-save 16-bit and Adam7 files first. Animated WebP requires a browser with ImageDecoder support.
• At most 20 MiB total input, four files, 4096 pixels per side, four megapixels per frame, 20 million decoded input canvas pixels, 20 million output canvas pixels and 300 output frames. Output is at most 40 MiB; one cycle is at most five minutes. The cancellable worker has a 120-second overall deadline.
• One source cycle is used per input. Cumulative source boundaries round to milliseconds; zero stored delays become 100 ms. GIF output rounds cumulative boundaries to 10 ms and rejects any collapsed visible interval. Very short delays may still be clamped by viewers.
• APNG retains composited eight-bit RGBA samples; GIF thresholds alpha at 128 and reduces each frame to at most 255 opaque colors; WebP RGB is lossy at every quality level while alpha is retained. Metadata and source profiles are not copied. Downloaded timing JSON explains output delays and loop semantics.
• One caption block of one to four lines, up to 500 characters, placed in a chosen millisecond interval of the first source cycle. Existing burned-in text cannot be edited.
• Pinned Noto Sans Bold is downloaded from the immutable local tool assets and verified before use. Unsupported code points fail visibly rather than falling back to a system font. No claim of all-language or complex-script coverage; browser rasterization may differ slightly across platforms. The caption and outline must fit inside the canvas.